Japanese Patent No. 4464260 has proposed a technique associated with a radiation imaging apparatus including a sensor panel having a plurality of photoelectric conversion elements and a scintillator layer. The sensor panel includes electrical contacts electrically connected to the photoelectric conversion elements. Wiring members for reading out signals from the sensor panel to the outside are connected to the electrical contacts. The wiring members are pressure-bonded to the electrical contacts. A supporting substrate is adhered to the reverse surface of the sensor panel with an adhesive agent. Gaps are provided between the supporting substrate and portions, of the sensor panel, on which the electrical contacts are arranged. When pressure-bonding the wiring members, rigid members are inserted into the gaps. After the wiring members are mounted, the rigid members are removed from the gaps, and buffer members are inserted instead of the rigid members. When pressure-bonding the wiring members, mounting the rigid members suppresses the deformation of the sensor panel which is caused by pressure-bonding, and mounting the buffer members in the other case improves the impact resistance of the sensor panel.